Spaceflight Insider

ULA preps Atlas V 421 to launch classified NROL-52 mission

An Atlas V rocket is rolled to the pad at Space Launch Complex 41. Launching in the 421 configuration, the Atlas V is carrying the NROL-52 mission for the National Reconnaissance Office. Photo and Caption Credit: ULA

An Atlas V rocket is rolled to the pad at Space Launch Complex 41. Launching in the “421” configuration, the Atlas V is carrying the NROL-52 mission for the National Reconnaissance Office. Photo and Caption Credit: Jeff Spotts / ULA

CAPE CANAVERAL, Fla. — United Launch Alliance (ULA) is preparing to send a geosynchronous communications satellite into space on behalf of the National Reconnaissance Office (NRO) via an Atlas V 421 rocket from Cape Canaveral Air Force Station’s Space Launch Complex 41. Liftoff of the NROL-52 mission is scheduled to take place on Thursday, Oct. 5, 2017.

Atlas-V / NROL-52 mission rocket

Photo Credit: Ben Cooper / ULA

The launch window is slated to open at 4:07 a.m. EDT (08:07 GMT) and last for about 90 minutes. If everything goes according to plan, the 191-foot (58-meter) tall rocket will unleash some 1.6 million pounds-force (7,100 kilonewtons) of thrust at liftoff to rise into the black of space from Space Launch Complex 41 at Cape Canaveral Air Force Station.

While the exact nature of the spacecraft is unknown, it is speculated to be the second spacecraft in the fourth generation of the Satellite Data System (SDS). Earlier versions of the SDS operated in a geosynchronous orbit to relay data from surveillance satellites in low-Earth orbit.

Headquartered in Chantilly, Virginia, the NRO operates a number of satellite constellations in various orbits to conduct intelligence-related reconnaissance for the United States. The organization supports policymakers, the Armed Services, the Intelligence Community, the Departments of State, Justice, and Treasury, as well as various civil agencies.

Some of the capabilities of the reconnaissance agency include monitoring the proliferation of weapons of mass destruction; tracking international terrorists drug traffickers, and criminal organizations; the development of highly accurate military targeting data and bomb damage assessments; supporting international peacekeeping and humanitarian relief operations; and assessing the impact of natural disasters, such as earthquakes, hurricanes, floods, and fires.

The Atlas V 421

Launching in the “421” configuration, the two-stage Atlas V (the rocket currently at the pad is designated AV- 075) has a 13.7-foot (4.2-meter) wide payload fairing, two strap-on solid rocket motors, and a single engine Centaur upper stage. The first stage of the vehicle, known as the Common Core Booster, has a single Russian-built RD-180 engine. The 860,000 pounds-force (3,800 kilonewtons) of thrust from this engine will be directed out via two nozzles at the launch vehicle’s base.

The Common Core Booster is 12.5 feet (3.8 meters) in diameter and about 107 feet (32.5 meters) long. It holds about 73,800 U.S. gallons (280,000 liters) of rocket-grade kerosene, known as RP-1, and liquid oxygen.

The two side-mounted boosters are 5.2 feet (1.6 meters) wide and 65.5 feet (20 meters) tall. They will burn for about 91 seconds before falling away 38 seconds later. The core stage will continue to burn until the 4-minute, 10-second mark after liftoff.

Once the fuel in the Common Core Booster is consumed, it will fall away and the Centaur upper stage will take over. It has a single restartable RL10C-1 engine that will burn liquid hydrogen and liquid oxygen for up to 14 minutes.

However, as this is a classified flight, coverage of the NROL-52 mission will end just before payload fairing separation, which will occur 4 minutes, 34 seconds after liftoff. As such, the exact duration of the upper stage burn, or the exact orbit the payload is being delivered to, is classified.

This will be the 656th launch for the Atlas program since 1957 and the 359th from Cape Canaveral. It will be the 74th flight of an Atlas V rocket since 2002 and the 16th time the vehicle has delivered a payload for the NRO.

So far, in 2017, five Atlas V rockets have sent payloads into space; the Oct. 5 launch will be the sixth. Two of those flights occurred at Vandenberg Air Force Base in California, while the rest were at Cape Canaveral.

Video courtesy of ULA



Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

Reader Comments

I would like to find out where to go to find where to see live internet coverage of your launches.
Keep up the great work and thanks for your attention.

Oct. 4, 2017

Hi Joe,
You can find it on our home page (it’s currently the top story in our left hand column). Also, if you click on our Countdown Clock, that should take you there as well.
Sincerely, Jason Rhian – Editor, SpaceFlight Insider

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